What Is a Hematoma?

A hematoma is an abnormal pooling of blood in the body under the skin that results from a broken or ruptured blood vessel. The most common symptoms of hematomas are pain and swelling.

Hematomas are more than simple bruises and can form anywhere in the body, but can be very serious if they happen in the head. The severity of a hematoma depends on the injury or condition that caused it.

A minor injury can cause skin discoloration while a more serious one can cause clotted blood to collect deep in a muscle, organ, or the skull—a condition that needs immediate medical attention and can even be life-threatening without treatment. 

Treatment for hematomas ranges from basic first aid to emergency surgery. Head injuries that cause hematomas are very concerning because there is a risk of traumatic brain injury.

This article will go over what causes hematomas, how they are treated, and how to prevent them.

Types of Hematoma

Hematoma types depend on the specific parts of the body where they form. 

• Abdominal: These hematomas can occur in the abdomen (intrabdominal) or the abdominal wall (usually from abdominal muscle bleeding). They can also cause blood to build up in other organs such as the kidneys and liver.
• Auricular: A hematoma in the ear can affect the blood supply and cause the tissues of the ear to die. It can also cause deformity (”cauliflower ear”).
• Intracranial: These hematomas happen in the head and there are several subtypes (e.g., epidural, subdural).
• Intramuscular: These hematomas are in the muscle tissue. They can be painful because there is inflammation, swelling, and irritation. If the blood supply in the muscle is affected, nerves can be harmed. This type of hematoma is often seen in the lower legs and lower arms.
• Septal: In this hematoma, blood collects in the area of the nose between the nostrils (septum). The cover of the septal cartilage (mucoperichondrium) separates from the cartilage, causing blood to pool. This type of hematoma is most often from a broken nose or a complication from septum surgery.
• Subungual: These hematomas happen when blood pools under a toenail or fingernail and can cause pressure and pain.
• Subcutaneous: These hematomas are under the skin and affect the shallow veins. People on blood-thinning medications are the most likely to get these hematomas. 

Which Hematomas Are The Most Serious?

A hematoma in the head is generally considered more serious than a hematoma in other parts of the body because it’s usually associated with traumatic brain injury.

The types of intracranial hematomas are:

• Intracerebral hematoma is when blood pools in the brain after an injury.
• Epidural or extradural hematoma happens when there is bleeding between the skull and the brain's protective covering (the dura). It is seen in skull fractures in children and adolescents because their dura is not as firmly attached to the skull as it is in adults.
• Subdural hematoma bleeding happens from the veins on the surface of the brain. The blood collects between the surface of the brain and the dura covering the brain.

Subdural hematomas can be acute or chronic:

• Acute subdural hematomas are from a traumatic injury and generally come on quickly. 
• Chronic subdural hematomas are small and happen repeatedly over time. They are more common in older adults, people who take anticoagulants, and people who misuse substances like alcohol.

Chronic hematomas are less likely than acute hematomas to cause a rapid increase of pressure in the skull. By the time symptoms are noticed, chronic subdural hematoma has often gotten very big.

Intracranial hematomas can grow slowly or quickly, but no matter how fast they grow, they can put pressure on the brain, which can lead to coma and even death if the injury is not treated.

Hematoma Symptoms

Hematomas near the skin cause a large patch of skin discoloration (typically dark red or black and blue) that happens because there is damage to the soft tissue. 

Hematomas also can cause symptoms like

• Pain, which may be felt deep inside the body
• Swelling
• Tenderness over the area of skin discoloration

Signs of Intracranial Hematomas 

Signs of more serious intracranial hematomas include:

• Headache
• Vomiting
• Drowsiness
• Dizziness
• Confusion
• Slurring of speech
• Unequal pupil size 
• Paralysis on the side of the body opposite the hematoma

Most intracranial hematomas come on fast after an injury and cause symptoms within minutes. However, they can also appear hours, days, or even weeks later.

Causes

Hematomas are caused by an injury to the body—usually a hard impact—that damages blood vessels and lets blood leak out and collect or “pool” in the spot. 

Intracranial hematomas often happen with a serious head injury, but can also happen with minor head injuries in people who have problems with blood clotting or weakened blood vessels from age and/or excessive alcohol use.

Some medications, supplements, and treatments can also make a person more likely to get hematomas. 

For example, medications that are used to thin the blood (anticoagulants) to help prevent blood clots (like warfarin or coumadin) make it easier for you to bleed. Aspirin is also a common medication that can make bleeding more likely. There are also other kinds of medications that can make you more likely to easily bleed or bruise, including some antidepressants, steroids, and some drugs used to treat cancer.

There are also some herbs and natural supplements that might make you bruise or bleed more easily, like garlic and ginko. The effects of these herbs can be greater if you also take medications that thin your blood (like aspirin).

Diagnosis

Less-serious hematomas do not always require medical care, though a healthcare provider can usually diagnose it just by looking at the injury. 

Hematomas near major organs, especially intracranial hematomas, need to be diagnosed with imaging technology.

Head hematomas usually are diagnosed with computed tomography (CT) scan or magnetic resonance imaging (MRI). 

These scans help providers see the source of the bleeding and the severity of the injury. They can help determine what treatment is necessary, and, in some cases, needed to save a person’s life.

Treatment

Treating a simple, mild, hematoma is similar to treating other soft tissue injuries. Using the R.I.C.E method (rest, ice, compression, elevation) is recommended. Apply ice to the area for 15 minutes, several times per day.

Hematoma pain and swelling can be treated with over-the-counter (OTC) pain medications. Aspirin should not be used if you have a hematoma because the drug can make you bleed more easily.

Treatment for more serious hematomas will depend on the size of the hematoma, whether there is still bleeding, and other problems the hematoma might be causing or could cause. Treatment can vary from first aid to major surgery.

Intracranial hematomas may have to be treated with surgery to allow blood to drain and decrease pressure in the brain. This can include drilling a small hole in the skull or performing a craniotomy to make a larger opening.

Prognosis

Mild hematomas and contusions will usually heal in about five days. A large hematoma may last weeks to months and as it heals it will change color and slowly shrink.

For more serious hematomas, especially those that involve a head injury, the outlook for recovery depends on how severe the injury was and how soon it was treated. 

It can take many months for people to recover from head injuries and in some cases, recovery takes years. Some kinds of brain injuries leave lasting changes that people have to learn to live with. 

How to Prevent a Hematoma

The key to preventing hematomas is to make sure that you are safe when doing activities where they’re likely to happen, like sports. That could mean something as simple as wearing a helmet when you’re riding your bike or making changes in your home to help you avoid falls. 

If you have a medical condition or take a medication that affects blood clotting, check with your healthcare provider. Talk with them about your risk for hematomas and other bleeding problems and steps you should take if you get hurt. 

Summary

Hematomas can range from harmless to life-threatening, depending on what caused them and what part of the body they affect. 

People who are most at risk for hematomas, like older adults, people with bleeding disorders, or people taking blood-thinning medications, need to take preventive steps to avoid these injuries. 

Head injuries that cause hematomas can be very serious, which is why you should always wear a helmet when doing sports or other activities that put your head at risk.